Apparatus for feeding blanks from the bottom of a stack

ABSTRACT

A feeder mechanism is provided to feed envelope blanks having rectangular or triangular bottom flap portions from the bottom of a stack while maintaining register. A sucker shaft is rotatably mounted within a hollow feed cylinder that has an elongated longitudinal opening. The sucker shaft has radially extending protuberances that extend through the cylinder opening and beyond the periphery of the feed cylinder. The protuberances extend upwardly through the cutout segments of the feeder disc to a position adjacent the front edge of the bottom blank. The protuberances, by suction, engage the entire front end portion of the bottom blank while the front edge portion of the stack is supported by a support device. By rotation of both the feed cylinder and the sucker shaft at different peripheral speeds and in opposite directions, the front edge of the bottom blank is bent downwardly into the feed cylinder. An edge of the cylinder opening engages the blank upper surface and continues to bend the front end portion of the blank downwardly. A cylindrical pressure segment urges the blank against the peripheral surface of the feed cylinder to separate the bottom blank from the stack and feed the blank to an impression cylinder. The peripheral surface of the feed cylinder adjacent the longitudinal opening has suction ports therein to engage the blank to the peripheral portion of the feed cylinder.

United States Patent 72] inventors Eliot S. Smlthe New York, N.Y.; Herbert M. Helm, l-loilidaysburg, Pa. [21 Appl. No. 827,424 [22] Filed May 23, 1969 [45] Patented Aug. 17, 1971 1 73] Assignee F. L. Smithe Machine Company, Inc. Duncansville, Pa.

I541 APPARATUS FOR FEEDING BLANKS FROM THE BOTTOM 01- A STACK I4 (.lnllnu, ll Drawing Flux. l52| 11.5.1.1 271/29 [51] B65h3/l0 151)] FleidolSearch 271/29 [56] References Cited UNITED STATES PATENTS 999,936 8/1911 Wines 271/29 1,312,539 8/1919 Harrold 271/29 1,682,276 8/1928 Hartman etal.... 271/29 1,875,189 8/1932 Winkler et a1 271/29 1,939,193 12/1933 Wink1ereta1..... 271/29 2,425,936 8/1947 Hepp r. 271/11 3,380,353 4/1968 Mittermayer 271/29 X Primary Examiner-Joseph Wegbreit Attorney-Stanley J. Price, Jr.

ABSTRACT: A feeder mechanism is provided to feed envelope blanks having rectangular or triangular bottom flap peripheral surface of the feed cylinder adjacent the longitudinal opening has suction ports therein to engage the blank to the peripheral portion of the feed cylinder.

PAIENIEB me I 1 Ian SHEET 1 [IF 2 INVENTORS HERBERT W. #51.

flu/r Mummy ELIOT s. smru: I] A;

APPARATUS FOR FEEDING BLAN KS FROM THE BOTTOM OF A STACK BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method and apparatus for feeding blanks from the bottom of the stack and more particularly to a method and apparatus for feeding wallet-type and commercialtype envelope blanks into an envelope machine in register.

2. Description of the Prior Art U.S. Pat. No. 3,281,142 entitled Device For Feeding Envelope Blanks" discloses apparatus for feeding conventional envelope blanks having a triangular bottom flap by supporting the front edge of the triangular bottom flap on a movable support and engaging the undersurface of the blank by a cam-actuated suction device. The suction device moves the front edge of the blank downwardly toward a feed drum located therebeneath. A deflector similar to that illustrated in U.S. Pat. No. 2,954,225 engages the downwardly bent front edge of the blank bottom flap and urges the blank against the feed drum and the bottom blank is withdrawn from the stack by the feed drum with the deflector urging the blank against the peripheral surface of the rotating feed drum. There is also provided a movable separator that supports the front edge of the triangular bottom flap and supplied timed air to separate the front edge of the bottom blank from the stack while the undersurface of the bottom blank is engaged by the suction device.

U.S. Pat. No. 1,939,193 discloses apparatus for withdrawing single sheets from a stack by means of a sucker shaft positioned within a hollow feed cylinder. The stack is supported by a stack plate with the front edge portions supported by the rotating feed cylinder.

SUMMARY OF THE INVENTION The hereinafter-described invention is directed to a method and apparatus for feeding blanks from the bottom of a stack while maintaining register. The undersurface of the bottom blank adjacent the front edge portion is engaged by radially extending protuberances on a sucker shaft positioned within a hollow feed cylinder. The front edge of the stack is supported by a pair of rotating discs with cutout segments and a cam-ac tuated separator member. The protuberances on the sucker shaft extend upwardly through an opening in the feed cylinder and between the cutout segments of the rotating supporting discs and engage the undersurface of the bottom blank adjacent the front end thereof while the front edge of the stack is supported by the separator. Rotation of the sucker shaft and feed cylinder in opposite directions bends the front edge ofthe bottom blank downwardly into the sucker shaft and feed cylinder in opposite directions bends the front edge of the bottom blank downwardly into the internal portion of the feed cylinder. Continued rotation of the feed cylinder moves an edge portion into abutting relation with the upper surface of the bottom blank to further bend the front edge of the bottom blank downwardly. The feed cylinder has a plurality of suction ports adjacent the edge of the cylinder and the upper surface of the bottom blank is secured to the periphery of the feed cylinder by the suction ports. A pressure cylinder urges the bottom blank against the periphery of the feed cylinder to withdraw the bottom blank from the bottom of the stack.

Considerable difficulty has been encountered in the past in feeding envelope blanks having a rectangular bottom flap into an envelope machine, especially at high speeds. Although the feed mechanism disclosed in U.S. Pat. Nos. 3,28I,l42 and 2,954,225 operates satisfactorily with envelope blanks having a triangular bottom flap, there is a tendency with this feed mechanism for the ends of a wallet-type envelope blank to billow and jam the feeding device. Further, the sucker device illustrated in the above-named patents is cam actuated and is subject to rapid wear at high speeds. The feeder device disclosed in U.S. Pat. No. 1,939,193 supports the sheet front edge portion on the feed cylinder which limits substantially the rate of feed of the blanks from the stack. With the hereinafter-described invention, it is now possible to feed wallet-type envelope blanks into an envelope machine in register at high speeds without the bottom flap front edge portions billowing and causing jams and malfunctions in the feeding device.

Accordingly, the principal object of this invention is to provide a method and apparatus for feeding blanks from the bottom of the stack wherein the entire front edge of the bottom flap is engaged by a portion of the feeding device.

Another object of this invention is to provide a high-speed feeder device that has apparatus for positively removing the bottom blank from the stack and maintaining the bottom blank in register for subsequent operations thereon in the envelope machine.

These and other objects and advantages of this invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top plan view of the feeder device with the stack of blanks illustrated in phantom.

FIG. 2 is a view in section taken along the lines 2-2 of FIG. I.

FIGS. 3, 4, 5, 6, 7 and 8 illustrate sequentially the manner in which the feeder device removes the bottom blank from the stack.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and particularly FIGS. 1 and 2, there is illustrated in detail a sheet or blank feeder device generally designated by the numeral I0 that is arranged to remove the bottom blank 12 from a stack of blanks I4. The blanks in stack 14 are preferably envelope blanks having a body portion 16, end flaps 18, a seal flap 20 and a bottom flap 22. The feeder device 10 is suitable for use with conventional envelope blanks that include a triangular seal flap but is particularly useful with the wallet-type envelope blanks that include a rectangular bottom flap 22 with an elongated front edge portion 24. The wallet-type envelope blanks have recessed portions 26 and 28 between the seal flap 20 and the end flaps IS.

A stack-supporting member 30 is arranged to support the major portion of the stack I4 and has a pair of upstanding register rods 32 and 34. The blank recessed portions 26 and 28 abut the vertical rods 32 and 34 and provide a register reference for subsequent feeding of the blanks to the printing portion of an envelope machine. A pair of rotating support discs 36 and 38 are suitably secured to vertical shaft members 40 and 42 and are arranged to support the front portion of the stack as illustrated in FIG. 1. The disc 36 rotates in a counterclockwise direction and the disc 38 rotates in a clockwise direction in timed relation with each other and in timed relation with other later described components of the feeding device II]. The discs 36 and 38 have cutout portions or segments 44 which permit the sucker shaft protuberances that extend upwardly therebetween to remove the bottom blank I2 from the stack 14 when the discs are in the position illustrated in FIG. I.

A knifelike support 46 is provided to support the front edge 24 of the stack when the bottom blank I2 is being withdrawn therefrom by the sucker shaft, as later explained. There are also provided air nozzles 48 associated with the support knife 46. Air is supplied to the nozzles 48 when the support is in the position illustrated in FIG. I and supporting the front edge of the stack I4 to separate the front edges of the stack for removal of single blanks from the stack. When the support knife 46 is moved out of supporting relation to the stack 14', illustrated in FIG. 4, the air supply to nozzles 48 is off. The support knife 46 is connected to a bellcrank 50 that is pivoted about pivot shaft 52. A cam roller 54 follows a' rotating cam surface and reciprocates the support. The knife support 46 is arranged to pivot inwardly beneath the stack of blanks l4 and outwardly away therefrom in timed relation to the other components of the feeder device 10. The supply of air to the nozzles 48 is further controlled to supply air only when the sup port knife 46 is beneath the stack of blanks 14. One embodiment of the support knife 46 and air nozzles 48 is illustrated and described in U.S. Pat. No. 3,281,142, assigned to the assignee of the instant invention.

The stack-supporting member 30 includes an arcuate guide plate 56 which supports and guides the bottom blank I2 as it is removed from the stack I4 and fed to the printing portion of the envelope machine. A hollow feed cylinder 58 is positioned beneath the blank front edge 24 and has a sucker shaft 60 rotatably mounted therein. The cylinder 58 has an elongated rectangular opening 62 in the periphery with an edge portion 64 that will be referred to as the pullout segment of the feed cylinder 58. There is also provided in the periphery -of feed cylinder 58 a plurality of suction apertures or ports 66 positioned longitudinally adjacent to the pullout segment 64. Suction is applied from a vacuum device (not shown) through the ports 66 by means of a segmented valve having a valve stator 68 and a valve rotor 70. Suitable passageways are provided between the valve stator 68 and the valve rotor 70 to connect the open passageways and vacuum device to the ports 66 when the feed cylinder 58 is in a preselected angular position relative to the stack 14.

The sucker shaft 60 is rotatably mounted in the feed cylinder 58 and is drivingly connected to the feed cylinder 58 to rotate relative thereto. The sucker shaft 60 has a gear 72 nonrotatably secured to its end portion that meshes with an idler gear 74 suitably journaled on the feed cylinder 58. A gear 76 is nonrotatably mounted about shaft 78 of feed cylinder 58 and is fixed in respect to the machine frame. The gear 76 meshes with the idler gear 74 and forms a gear train that provides rotation for gear 72 and sucker shaft 60 relative to the feed cylinder 58. The above gear train is similar to a planetary gear train and gear 76 may be considered a sun gear and the gear 72, a planet gear. The velocity ratio between the sucker shaft 60 and die feed cylinder 58 may vary as, for example, a velocity ratio of 3: l 2:l or 4:l may be provided depending on the gear ratio. One of the essential characteristics of the gear arrangement is that the sucker shaft 60 always assumes the position illustrated in FIG. 2 when the feed cylinder 58 is in the position illustrated in FIG. 2 relative to the stack l4v The sucker shaft 60 has a plurality of protuberances 80, 82 and 84 extending radially therefrom and a longitudinal passageway 86 suitably connected to a vacuum device that is arranged to apply a suction through passageway 86 while the sucker shaft 60 is in a preselected position relative to the stack 14. The protuberances 80, 82 and 84 each have a plurality of vertical passageways 88 therethrough that provide areas of negative pressure on the upper surface 90 when a suction is applied through the longitudinal passageway 86. The protuberances 80, 82 and 84 are preferably fabricated from a flexible material such as urethane polymer, rubber or other readily deformable and resilient material. It is desirable for proper removal of the lower blank 12 that the protuberances 80, 82 and 84 extend outwardly beyond the periphery of the feed cylinder 58 to a location adjacent the bottom of the stack I4 so that the underside of the bottom blank 12 will be engaged to the protuberances 80, 82 and 84.

With a 3:l ratio between the gears 72 and 76, the sucker shaft 60 makes three revolutions for each revolution of the feed cylinder 58. Thus the protuberances 80, 82 and 84 extend outwardly beyond the periphery of feed cylinder 58 at three locations during each revolution of feed cylinder 58. It is essential that adequate clearance is provided between the other elements of the feed mechanism It) and envelope machine to prevent damage by the protuberances on the sucker shaft 60 to either the other elements of the feed mechanism 10, the envelope machine or the sucker shaft 60 and feed cylinder 58. It is preferable however, that the protuberances be fabricated of a flexible material to prevent damage due to an inadvertent mistiming of the machine elements or paper jams in the machine.

As illustrated in FIG. 2, the bottom blank 12 is removed from the stack 14 by the sucker shaft 60 and is transferred to an impression cylinder 92 or other type of transfer cylinder. A plurality of vacuum ports 94 are provided on the impression cylinder 92 or other type of transfer cylinder. A plurality of vacuum ports 94 are provided on the impression cylinder 92 to engage the front edge of the bottom blank 12 as it is transferred thereto. There is also provided a pressure cylinder 96 has a peripheral segment 98 that is arranged to exert a positive pressure against the peripheral surface 100 of feed cylinder 58 to positively pull the bottom blank 12 from beneath the stack I4 and maintain the blank in register as it is removed from the bottom of stack 14 while the upper surface of the bottom blank 12 is engaged to the peripheral surface of feed cylinder 58 by suction through ports 66. The impression cylinder 92, pressure cylinder 96 and feed cylinder 58 rotate in timed relation to each other to feed the blanks removed from the stack 14 to the impression cylinder 92 without changing the register controlled by the vertical register posts 32 and 34.

OPERATION Now referring to FIGS. 3, 4, 5, 6, 7 and 8, the method of operation of the improved feeder mechanism 10 will be described in detail. In FIG. 3, the sucker shaft 60 is positioned with he protuberance extending upwardly beyond the periphery of feed cylinder 58 between the support discs 36 and 38 beneath the front edge 24 of bottom blank 12. The support knife 46 extends beneath the bottom blank 12 and supports the front edge of the stack 14 including the bottom blank 12. The discs 36 and 38 are in the position illustrated in FIG. I. The airblast supplied through the nozzles 48 separates the bottom blank 12 from the remaining blanks in the stack 14 while suction is applied through sucker shaft 60 to engage the undersurface of the bottom blank 12 along the length of the front edge 24 by means of the three protuberances 80, 82 and 84.

As the feed cylinder 58 rotates in a counterclockwise direction, the cam-actuated support knife 46 moves outwardly away from beneath the stack 14 as illustrated in FIG. 4. The protuberances on sucker shaft 60 have engaged the bottom blank front edge 24 and the sucker shaft 60 has rotated in a clockwise direction a given angle which, in this instance, is three times as large as the angle of rotation of the feed cylinder 58. It should be noted that the bottom blank 12 in FIG. 4 remains fixed beneath the stack 14 and only the front edge 24 is being bent downwardly by the rotation of sucker shaft 60.

As illustrated in FIG. 5, the knife support 46 is again repositioned beneath the front edge of the stack 14 and the discs 36 and 38 have rotated so that the discs have moved under the stack between the stack 14 and the bottom blank 12. In FIG. 5, the sucker shaft 60 has rotated to the position illustrated and has released the undersurface of the bottom blank 12. The front edge of the bottom blank is within the feed cylinder 58 and further rotation of feed cylinder 58 moves the edge or the pullout segment 64 into abutting relation with the upper surface of the blank and continues to bend the blank downwardly away from the stack I4 as is illustrated in FIGS. 6 and 7. Further rotation of feed cylinder 58 and pressure cylinder 96, as illustrated in FIG. 8, moves the pressure surface 98 of pres sure cylinder 96 and the blank against the surface of feed cylinder 58 to frictionally engage the blank [2 to the periphery of feed cylinder 58 and with further rotation, positively remove the bottom blank 12 from beneath the stack [4 while maintaining register. While in this position relative to the pressure segment 98, suction is applied through ports 66 to engage the upper surface of bottom blank 12 to the periphery of feed cylinder 58. The feed cylinder 58 continues to rotate beyond the position illustrated in FIG. 8 with the bottom blank secured thereto by suction through ports 66 until the underside of the bottom by suction through cylinder 92. Suction is then turned 05 in ports 66 and the blank released from feed cylinder 58 and transferred in register to the transfer or impression cylinder 92. The cycle as previously described is repeated at high speeds to remove the blanks separately from the bottom of the stack 14. With this arrangement, it is now possible to positively and accurately remove the envelope blanks from the bottom ofa stack at high speed without jam-ups and still maintain register. The 38 to support the front shaft 60 extend between the cutaway portions on the discs 36, 38 and the timed rotation of the feed cylinder 58 and sucker shaft 60 maintains the bottom blank in register while the front edge of the bottom blank is being bent downwardly relative to the stack 14. The pressure segment 98 and the suction ports 66 on the feed cylinder 58 maintain the blank in register as it is withdrawn from beneath the stack and transferred to the transfer cylinder 92.

For brevity and clarity, certain of the components have been illustrated diagrammatically; the control devices for rotating and actuating the components in timed relation to each other and the device for applying suction through the various suction ports in proper sequence have been omitted, the function of these devices will be apparent from the previous description and various conventional control devices may be used.

According to the provisions of the patent statutes, we have explained the principle, preferred construction and mode of operation of our invention and have illustrated and described what we now consider to represent its best embodiment.

We claim:

1. Apparatus for feeding blanks from comprising,

support means operable to support a stack of blanks,

a feed cylinder positioned beneath the front edge of said stack,

a sucker shaft rotatably mounted in said feed cylinder,

said sucker shaft having a plurality of protuberances extending radially therefrom and extending during a portion of the rotation of said feed cylinder beyond the periphery of said feed cylinder,

said protuberances having suction ports therein,

vacuum means to exert a suction on said suction ports,

said protuberances on said sucker shaft operable to engage the undersurface of said bottom blank by suction through said suction ports at a location beyond the periphery of said feed cylinder,

means to rotate said feed cylinder and said sucker shaft to engage the undersurface of said bottom blank by said sucker shaft protuberances extending beyond the periphery of said feed cylinder and bending the front end portion ofsaid bottom blank downwardly while said bottom blank rear portion remains fixed relative to said stack,

blank-engaging means including a first portion thereon operable to engage said bottom blank upper surface adjacent said bottom blank front end portion and further bend said bottom blank downwardly while said bottom blank rear edge portion remains fixed relative to said stack, and

said blank-engaging means including a second portion thereon operable to thereafter engage said bottom blank upper surface at a location spaced rearwardly from said blank front end portion and move said bottom blank relative to said stack into a blank transfer device.

2. Apparatus for feeding blanks from the bottom ofa stack as set forth in claim I in which said feed cylinder includes,

the bottom of a stack a longitudinal opening in the periphery thereof with a sheetengaging end portion,

said sucker shaft positioned within said feed cylinder and arranged to rotate in a direction opposite to said feed cylinder and in timed relation thereto,

said sucker shaft protuberances operable to engage the undersurface of said bottom blank adjacent said bottom blank front edge portion and upon rotation of said sucker shaft and said feed cylinder to move said blank front edge portion downwardly into said feed cylinder,

said feed cylinder sheet-engaging edge portion operable to engage the upper surface of said bottom blank and upon further rotation of said feed cylinder move said bottom blank front edge portion downwardly into said feed cylinder.

3. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which,

said feed cylinder includes suction means in the periphery thereof, said suction means operable to engage said bot tom blank to said feed cylinder surface so that upon rotation of said feed cylinder said bottom blank is withdrawn from beneath said stack.

4. Apparatus for feeding blanks as set forth in claim 2 in which,

said feed cylinder includes suction means along the periphery thereof extending longitudinally adjacent said sheet-engaging edge portion of said longitudinal opening, said suction means operable to engage the upper surface of said bottom blank after said bottom blank undersurface is disengaged from said sucker shaft protuberances 5. Apparatus for feeding blanks from the bottom of a stack as set forth in claim I in which,

said blank-engaging means to engage said bottom blank upper surface includes,

a pressure cylinder segment positioned adjacent to said feed cylinder, said feed cylinder and pressure cylinder segment operable to rotate in opposite directions in timed relation,

said pressure cylinder segment operable to urge said bottom blank against said feed cylinder periphery and withdraw said bottom blank from said stack.

6. Apparatus for feeding blanks from the bottom of a stack as set forth in claim I in which said feed cylinder includes,

suction ports in the periphery thereof,

said feed cylinder suction ports operable to engage the undersurface of said bottom blank and transfer said bottom blank from said feed cylinder to other blank-engaging means positioned therebelow.

7. Apparatus for feeding blanks from the bottom of a stack as set forth in claim I in which said support means includes,

a pair of spaced rotatable discs positioned beneath the front portion of said stack, said discs having cutout segments, said discs operable to rotate in timed relation and to release the bottom blank to said blank-engaging means when said cutout segments oppose each other.

8. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which said support means includes,

a support knife positioned beneath the front edge of said stack,

said support knife operable to support the front edge of said stack while said blank-engaging means engages the undersurface of said bottom blank,

said support knife operable to move reciprocally from under said stack and release said bottom blank.

9. Apparatus for feeding blanks from the bottom of a stack as set forth in claim I in which said support means includes,

a pair of s aced rotatable discs positioned beneath the front portion of said stack, said discs having cutout segments, said discs operable to rotate in timed relation and to release the bottom blank to said blankengaging means when said cutout segments oppose each other,

a support knife positioned beneath the front edge of said stack,

from the bottom of a stack said support knife operable to support the front edge of said stack while said blank-engaging means engages the undersurface of said bottom blank, said support knife operable to move reciprocally from under said stack and release said bottom blank. 10. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 9 in which,

said protuberances on said sucker shaft extend radially upwardly beyond the periphery of said feed cylinder and through the cutout segments of said rotating discs to a location adjacent the undersurface of said bottom blank. 11. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 9 in which,

said feed cylinder includes suction means in the periphery thereof, said suction mean operable to engage said bottom blank to said feed cylinder surface so that upon rotation of said feed cylinder said bottom blank is withdrawn from beneath said stack. 12. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 9 in which,

said feed cylinder includes suction means on the periphery thereof extending longitudinally adjacent said sheet-engaging edge portion of said longitudinal opening,

said suction means operable to engage the upper surface of said bottom blank after said bottom blank undersurface is disengaged from said sucker shaft,

a pressure cylinder segment positioned adjacent to said feed cylinder, said feed cylinder and said pressure cylinder segment operable to rotate in opposite directions in timed relation,

said pressure cylinder segment operable to urge said bottom blank against said feed cylinder periphery and withdraw said bottom blank from said stack.

13. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which,

said protuberances on said sucker shaft are formed of a deformable resilient material.

14. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 2 in which,

the velocity ratio of said sucker shaft and said feed cylinder is such to position the protuberances on said sucker shaft adjacent the underside of said bottom blank during each revolution of said feed cylinder.

@333 UNITED STATES PATENT OFFICE CERTIFICATE OF I CORRECTION Patent No. 3 599,97 Dated August 17, 1971 Inventor(s Eli ot S Smithe and Herbert W. Helm It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the title page, column 1, Inventor's name "Herbert M. Helm" should read Herbert W. Helm-. Column 1, line 29, "triangular bottom flap and supplied timed air" should read triangular bottom. flap and supplies timed air-. Column 3, line-54, before 'The' insert l4.-. Column 4, line 13, aftef the numeral '96 insert the following: which is also preferably fabricated from a urethane polymer or other compressible material. The pressure cylinder 96-; line 31, "with he protuberance 80" should read -with the protuberance 80.

Signed and sealedthis 22nd day of February 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOITSCHALK Attesting Officer Commissioner of Patents 

1. Apparatus for feeding blanks from the bottom of a stack comprising, support means operable to support a stack of blanks, a feed cylinder positioned beneath the front edge of said stack, a sucker shaft rotatably mounted in said feed cylinder, said sucker shaft having a plurality of protuberances extending radially therefrom and extending during a portion of the rotation of said feed cylinder beyond the periphery of said feed cylinder, said protuberances having suction ports therein, vacuum means to exert a suction on said suction ports, said protuberances on said sucker shaft operable to engage the undersurface of said bottom blank by suction through said suction ports at a location beyond the periphery of said feed cylinder, means to rotate said feed cylinder and said sucker shaft to engage the undersurface of said bottom blank by said sucker shaft protuberances extending beyond the periphery of said feed cylinder and bending the front end portion of said bottom blank downwardly while said bottom blank rear portion remains fixed relative to said stack, blank-engaging means including a first portion thereon operable to engage said bottom blank upper surface adjacent said bottom blank front end portion and further bend said bottom blank downwardly while said bottom blank rear edge portion remains fixed relative to said stack, and said blank-engaging means including a second portion thereon operable to thereafter engage said bottom blank upper surface at a location spaced rearwardly from said blank front end portion and move said bottom blank relative to said stack into a blank transfer device.
 2. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which said feed cylinder includes, a longitudinal opening in the periphery thereof with a sheet-engaging end portion, said sucker shaft positioned within said feed cylinder and arranged to rotate in a direction opposite to said feed cylinder and in timed relation thereto, said sucker shaft protuberances operable to engage the undersurface of said bottom blank adjacent said bottom blank front edge portion and upon rotation of said sucker shaft and said feed cylinder to move said blank front edge portion downwardly into said feed cylinder, said feed cylinder sheet-engaging edge portion operable to engage the upper surface of said bottom blank and upon further rotation of said feed cylinder move said bottom blank front edge portion downwardly into said feed cylinder.
 3. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which, said feed cylinder includes suction means in the periphery thereof, said suction means operable to engage said bottom blank to said feed cylinder surface so that upon rotation of said feed cylinder said bottom blank is withdrawn from beneath said stack.
 4. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 2 in which, said feed cylinder includes suction means along the periphery thereof extending longitudinally adjacent said sheet-engaging edge portion of said longitudinal opening, said suction means operable to engage the upper surface of said bottom blank after said bottom blank undersurface is disengaged from said sucker shaft protuberances.
 5. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which, said blank-engaging means to engage said bottom blank upper surface includes, a pressure cylinder segment positioned adjacent to said feed cylinder, said feed cylinder and pressure cylinder segment operable to rotate in opposite directions in timed relation, said pressure cylinder segment operable to urge said bottom blank against said feed cylinder periphery and withdraw said bottom blank from said stack.
 6. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which said feed cylinder includes, suction ports in the periphery thereof, said feed cylinder suction ports operable to engage the undersurface of said bottom blank and transfer said bottom blank from said feed cylinder to other blank-engaging means positioned therebelow.
 7. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which said support means includes, a pair of spaced rotatable discs positioned beneath the front portion of said stack, said discs having cutout segments, said discs operable to rotate in timed relation and to release the bottom blank to said blank-engaging means when said cutout segments oppose each other.
 8. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which said support means includes, a support knife positioned beneath the front edge of said stack, said support knife operable to support the front edge of said stack while said blank-engaging means engages the undersurface of said bottom blank, said support knife operable to move reciprocally from under said stack and release said bottom blank.
 9. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which said support means includes, a pair of spaced rotatable discs positioned beneath the front portion of said stack, said discs having cutout segments, said discs operable to rotate in timed relation and to release the bottom blank to said blank-engaging means when said cutout segments oppose each other, a support knife positioned beneath the front edge of said stack, said support knife operable to support the front edge of said stack while said blank-engaging means engages the undersurface of said bottom blank, said support knife operable to move reciprocally from under said stack and release said bottom blank.
 10. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 9 in which, said protuberances on said sucker shaft extend radially upwardly beyond the periphery of said feed cylinder and through the cutout segments of said rotating discs to a location adjacent the undersurface of said bottom blank.
 11. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 9 in which, said feed cylinder includes suction means in the periphery thereof, said suction mean operable to engage said bottom blank to said feed cylinder surface so that upon rotation of said feed cylinder said bottom blank is withdrawn from beneath said stack.
 12. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 9 in which, said feed cylinder includes suction means on the periphery thereof extending longitudinally adjacent said sheet-engaging edge portion of said longitudinal opening, said suction means operable to engage the upper surface of said bottom blank after said bottom blank undersurface is disengaged from said sucker shaft, a pressure cylinder segment positioned adjacent to said feed cylinder, said feed cylinder and said pressure cylinder segment operable to rotate in opposite directions in timed relation, said pressure cylinder segment operable to urge said bottom blank against said feed cylinder periphery and withdraw said bottom blank from said stack.
 13. Apparatus for feeding blanks from the bottom of a stack as set forth in claim 1 in which, said protuberances on said sucker shaft are formed of a deformable resilient material.
 14. Apparatus for feeding blanks from the bottom of a Stack as set forth in claim 2 in which, the velocity ratio of said sucker shaft and said feed cylinder is such to position the protuberances on said sucker shaft adjacent the underside of said bottom blank during each revolution of said feed cylinder. 